Combustion engines are machines that convert chemical energy stored in fuel into mechanical energy useful for generating electricity, producing thrust, or otherwise doing work. These engines typically include several cooperative sections that contribute in some way to this energy conversion process. In gas turbine engines, air discharged from a compressor section and fuel introduced from a fuel supply are mixed together and burned in a combustion section. The products of combustion are harnessed and directed through a turbine section, where they expand and turn a central rotor.
Heat generated from the combustion process, which takes place in a combustion chamber of a combustor, may shorten component life of various components exposed to that heat. This may occur particularly in situations in which a first component is attached to a second component whose temperature is substantially lower than that of the first component. A range of alternatives have been developed to maintain an acceptable component life for various components. These include making the components with an alloy that provides greater inherent heat stability, providing thermal barrier coatings (such as ceramic coatings), providing structural barriers, providing closed cooling systems that pass within a respective component, and providing open cooling systems.
As combustors of gas turbine engines are redesigned, such as to improve performance and reliability and to introduce new approaches toward such goals, certain design changes may result in a decreased component life for certain components. This may be due to changes in cooling that are introduced by design changes made for other reasons. To obtain a desired component life for all components of a newly designed combustor, appropriate innovations are required, and these may be conceived and achieved on a component by component basis, depending on particular circumstances.
In the present situation, a need was recognized for providing a new form of cooling using a defined flow of fuel gas.